Are the Payment Structure Calculations Correct?

i was considering selling on Envato Marketplace and i did a lit bit of calculation and something interesting and probably Mathematical Genius Calculation has come by i hope some of the experienced Authors and Staff can shed some light

FinalDestiny said
Oh, lol, how much math for one simple question When calculating the rate, it takes the whole price, including the Envato part.
If a theme costs $45, when you sell it, it’s $45 in sales. When you reach $3,750 in sales, you go up 1 percent.

NuclearThemes said
If the payment rates changed based on your sales after commission total then it still wouldn’t be twice the effort ($150,000) to reach 70%.
That would mean that the commission would jump from 50% to 70% at $150,000 instead of going up in stages.